There is well known a control apparatus for a vehicle provided with an electric motor functioning as a drive power source, and a step-variable transmission which constitutes a part of a power transmitting path between the electric motor and drive wheels and which is placed in a selected one of a plurality of gear or speed positions with engagement of selected at least one of a plurality of coupling devices. A control apparatus disclosed in JP-2009-166643A is an example of a control apparatus for this type of vehicular power transmitting system. This control apparatus is configured to control the vehicular power transmitting system upon a shift-down action of the step-variable transmission to its first speed position in a coasting run of the vehicle, such that an output torque of a second electric motor connected to an input shaft of the step-variable transmission is increased to increase an input torque of the step-variable transmission, for thereby raising a rotating speed of the input shaft of the step-variable transmission toward a synchronizing speed in the first speed position, and an engaging pressure of a coupling device to establish the first speed position is raised to place the coupling device in its fully engaged position when the rotating speed of the input shaft has reached a target value.
By the way, the vehicle may be run in the rearward direction with a reverse drive torque of an electric motor which is opposite in direction of its transmission to a forward drive torque of the electric motor and which is generated when the step-variable transmission is placed in a forward-drive low-speed position (a first speed position, for example) of its plurality of speed positions. If the reverse drive torque of the electric motor is generated during a shift-down action of the step-variable transmission to the forward-drive low-speed position in a coasting run of the vehicle as a result of an operation of a shift lever from a forward drive position D to a reverse drive position R (namely, as a result of an operator's requirement for reverse running of the vehicle), that is, if a rise of an input speed of the step-variable transmission is stopped as a result of switching of the output torque of the electric motor from the forward drive torque to the reverse drive torque, the shift-down action of the step-variable transmission in the coasting run of the vehicle does not progress, giving rise to a problem of delayed generation of a reverse vehicle drive force (reverse vehicle drive torque).